1. Field of the Invention
This invention relates to a circuit breaker and, more particularly, it pertains to a rotatable, externally accessible knob for calibrating the bimetal member of the circuit breaker without the necessity of disassembling the circuit breaker housing.
2. Description of the Prior Art
Certain types of circuit breakers comprise mechanisms that are preliminarily calibrated and then completely enclosed by housing parts that are riveted or otherwise fixedly secured together. During assembly subsequent to the preliminary calibration some breakers fall out of calibration and it has been necessary to remove the rivets or other securing means in order to recalibrate the mechanism after which the housing parts are reassembled. During these operations the expensive electronics portion of the circuit breaker is jeopardized and often results in substantial loss of this portion as well as loss of the housing due to cracking, chipping, distortion, and misalignment of housing parts. As a result the prior method of calibrating a circuit breaker of the type involved has been unsatisfactory.